<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
      .left {
          float: left;
          width: 100px;
          height: 200px;
          background: red;
      }
      .right {
          float: right;
          width: 200px;
          height: 200px;
          background: blue;
      }
      .main {
          margin-left: 120px;
          margin-right: 220px;
          height: 200px;
          background: green;
      }
  </style>
</head>
<body>
<div class="container">
  <div class="left"></div>
  <div class="right"></div>
  <div class="main"></div>
</div>
</body>
</html>
